Adjustable eraser



March 25, 1947. I J. GERSTER-SE'ILER- 2,417,925

ADJUSTABLE ERASER Filed Jan. 28, 1943 INVENTOR. JACOB GERSTER-SEILER BYAGENT.

Patented Mar. 25, 1947 ADJUSTABLE ERASER Jakob Gerster-Seiler,Jegenstorf, Bern, Switzerland 8 Claims.

My invention relates to an eraser and more particularly to a devicecomprising a tubular holder and a longitudinal tip or stick of rubber orsimilar erasing material, inserted in said holder and projecting overone end of the holder, said rubber stick being slidable in the axialdirection of the holder whereby the projecting length of the rubber canbe adjusted and fresh erasing material can be fed after the consumptionof the projecting part, of the tip.

Objects of my invention are to provide an erasing tip of the kinddescribed which, durin the erasing operation, is reliably securedagainst being shifted into the holder or being turned in the same; toprovide for convenient re-adjustment of the projecting rubber end afterconsumption of the uttermost end of the rubber tip; and to accomplishthese results with handy, simple and inexpensive means.

According to my invention, a Strip or blade of a material harder thanthe rubber, preferably of non-oxidizing metal, is inserted between theholder and the rubber stick and serves as an anchor for said stick. Thisanchor strip may have various shapes, two of which are described in thefollowing description and illustrated in the accompanying drawing inwhich:

Fig. 1 shows an exemplifying embodiment of the invention, the holder andanchor strip being shown in a longitudinal cross-section.

Fig. 2 shows another exemplifying embodiment in the same manner.

Fig. 3 shows a view of the outer surface of the anchor strip used in theembodiment shown in Fig. 2.

Fig. 4 shows a view of the inner surface of the anchor strip used in theembodiment shown in Fig. 1.

Fig. 5 shows a cross-section taken along the line 5-5 in Fig. 1.

Fig. 6 shows a front view of the anchor strip seen from the right sidein Fig. 1.

Fig. '7 shows a rear view of the same anchor strip seen from the leftside in Fig. 1.

Fig. 8 shows a cross-section taken along the line 88 in Fig. 2.

Referring particularly to the embodiment shown in Figs. 1, 4, 5, 6, and'7, numeral I indicates a tubular holder having longitudinalindentations or grooves 2. In Fig. 1, the left end of the holder I isbroken off. This end is immaterial for the invention and may be adaptedfor holding a pencil.

A rubber stick 3 having the same or a slightly smaller diameter than theinner diameter of the 2 holder l is inserted in the other end of theholder l so that the outer end of 3 is free to be used for erasing. Thelength of the stick 3 is sufficient for feeding erasing material to theopen when the outer tip of the stock is consumed.

An anchor strip 4 is inserted between the inner surface of the holder land the rubber stick 3. The strip 4 has a width covering a section ofthe circumference of the stick 3 and a relatively small thickness. Theouter surface of the strip 4 is slightly concave so that this surfaceabout fits the inner surface of an indentation 2. The inner surface ofthe strip 4 is provided with a plurality of depressions 5, thelongitudinal crosssection of the strip thereby having a saw-like shape.The individual teeth of this saw-shape have sides relatively long andgradually recessing at the inner side (left side in Fig. 1) andconsiderably steeper at the front side (right side in Fig. 1). The innerend of the strip 6 terminates in a thin blunt edge 6. The outer end ofthe strip forms a knob or boss 1 extending to the outer side somewhatover the outer surface of the holder l. The outer rim of the holder isprovided with a recess or incision in which the boss I finds placewithout towering in axial direction over the rim of the. holder, Thisboss acts as a handle for pulling or pushing the strip 4 and, as a stopfor the inward motion of thesame.

A clip or resilient clamp 8 is affixed to the boss I and extends overthe outer surface of the holder I, the far end 9 of this clip touchingsaid surface. The clip is not indispensable, a modification without theclip 8 being also operable. But the clip constitutes an improvementinsofar as it makes the pulling and pushing of the strip 4 moreconvenient, contributes to secure theproper position of the strip at thewall of the holder l and, at the same time serves as means for carryingthe entire device inside or outside of a pocket or the like, the wall ofsuch pocket being clamped between the clip and the holder.

The embodiment shown in Figs. 2, 3 and 8 comprises a holder ll having acircular wall, a rubber stick l3 similar to the stick 3 in theembodiment described before, and an anchor strip M having depressionsI5, a thinned end edge l6 and a boss ll, the details l5, l6 and I"!being similar to the details 5, 6 and "I of the first embodiment. Thecross-section of the strip I4 is bordered by two arcs and, thus, hasabout a ship-like shape. The outer arc fits about the inner wall of theholder I I. The inner arc presses into the rubber stick 13. The clip 8of the first embodiment is replaced by a member is forming an eye l9.The advantages of these parts are about the same as those of the parts 8and 9, except that the eye has the additional advantage to provide meansfor convenient suspension of the entire device.

In order to secure the eraser stick 3 or l3 to the holder, the thin edge6 or IE of the anchor strip is introduced between the stick and theinner surface of the holder, and the boss I or IT is pushed inward untilthe strip reaches the position shown in the drawing. In this position,the uneven surface of the anchor strip engages frictionally the rubberstick and prevents the same from being turned or pushed farther inward.When, due to consumption of earring material, the projecting part of thestick becomes shorter than desired, the anchor strip together with therubber stick is pulled outward as far as suitable and. then, the anchorstrip is pushed back again to the original position.

I desire it understood that my invention is not confined to theparticular forms described, the same being merely illustrative, and maybe carried out in other ways without departing from the spirit of theinvention.

I claim:

1. An adjustable eraser comprising a tubular holder; 3, stick of erasingmaterial inserted in one end of aid holder; and an anchor strip insertedat one side between the inner surface of said holder and said erasingstick, and irictionally engaging said stick the other sides of saidstick touching said holder immediately whereby said stick can maintainits position relative to said holder while said anchor strip isinserted.

2. An adjustable eraser comprising a tubular holder having longitudinalgrooves impressed in its wall; a stick of erasing material inserted inone end of said holder; and an anchor strip inserted between the innersurface of said holder and said erasing stick, said anchor strip havingan outer surface curved correspondingly to the adjacent part of saidgrooved wall and having an inner surface frictionally engaging saidstick.

3. An adjustable eraser comprising a tubular holder having a recess inthe rim of one end; a stick of erasing material inserted in said end ofsaid holder; and an anchor strip inserted between the inner surface ofsaid holder and said erasing stick, frictionally engaging said stick andhaving a boss at one end, said boss extending laterally through saidrecess of said holder.

4. An adjustable eraser comprising a tubular holder; a stick of erasingmaterial inserted in one end of said holder; and an anchor stripinserted at one side between the inner surface of said holder and saiderasing stick, and having an uneven surface pressing into said stick theother sides of said stick touching said holder immediately whereby saidstick can maintain its position relative to said holder while saidanchor strip is inserted.

5. An adjustable eraser comprising a tubular holder; a stick of erasingmaterial inserted in one end of aid holder; and an anchor strip insertedbetween the inner surface of said holder and said erasing stick, andhaving an uneven surface pressing into said stick and comprisingdepressions and projections alternating in longitudinal direction, thesides of said projections which are situated toward the outer end of therubber stick being steeper than the sides situated toward the inner endof said stick.

6. An adjustable eraser comprising a tubular holder; a stick of erasingmaterial inserted in one end of said holder; and an anchor stripinserted between the inner surface of said holder and said erasingstick, having an uneven surface pressing into said stick and having aninner end terminating in a thinned edge.

7. An adjustable eraser according to claim 3, further comprising a clipaflixed to said boss and having an end resiliently touching the outersur- REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 2,115,806 Frederick May 3, 19381,373,062 Faber Mar. 29, 1921

